87 octane gasoline, often called "regular" gas, is one of the most commonly used fuels in the United States. But what gives it that 87 rating is a word you've probably heard a time or two: Ethanol.

If you've ever fueled up in Colorado, you might have noticed something unusual about the gas octane ratings at the pump – specifically, the availability of 85-octane gasoline. This lower octane fuel ...

The answer is yes: You can mix 87 and 91 octane gasoline without blowing your engine to hell. With that out of the way, let's discuss what mixing different octane fuels does to your engine in terms of ...

DENVER — When you last filled up your car, do you remember how much it cost? You probably do because it was so high. There is a good chunk of Colorado drivers who could save money right away by ...

John Paul, AAA Northeast's Car Doctor, answers a question from a reader who recently visited a service station offering both 87 and 88 octane gas. The Car Doctor answers a question from a reader who ...

With the price of regular unleaded gasoline still in the $4-a-gallon range, the comparative price of premium is kind of a bargain at many stations. Really. When the price of regular surged this spring ...

DENVER (KDVR) — Gas pumps in some Western states look a little different than the rest of the country. Most states have the option of choosing octane ratings of 87 (regular), 88–90 (midgrade) and ...